On Wed, 10 Aug 2011 08:17:53 +0100, "N_Cook"
wrote:

I don't know if its relevant with these encoders but a few times I've found
with preset size pots that appear in audio mixers. The grease hardens and
then lifts the very feeble wipers of the pots. No track wear at all as the
wiper action is so slight , so why the grease ?

Good question. You might need a microscope to see the groves.

My guess(tm) would be to prevent oxidation and prevent the small
amounts of the resistance material from landing across contacts. I
also recall reading that it reduces pot noise improves the "feel" by
adding some drag, but that's mostly on the shaft, not the wiper.

This explains much:
http://www.nyelubricants.com/lubenotes/Lubenote_Potentiometers.pdf

Looks like they have different greases for different problems:
http://www.nyelubricants.com/applications/sensor_potentiometer.shtml
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558